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Phase Systems

By convention, the component predominantly in the bottom phase is plotted as the abscissa and the component predominantly in the top phase is plotted as the ordinate. The three methods are illustrated graphically in Fig. 2 (see Note 4). 1. In test tubes, using the appropriate stock solutions, prepare systems with different compositions of known weight. Account for the additional volume owing to titration, e.g., if 5 g systems are prepared, 10 mL test tubes should be used (see Note 5). As an...

Weigh out ca. 0.5 g of the ABEC resin prepared as outlined in Subheading 2.2.1., item 1. 2. Suspend the resin in ca. 30 mL of deionized water in a 50-mL beaker. 3. Sonicate the sample for 20 min to break up any clumps to facilitate packing the column. 4. Slurry pack the suspended resin into a small glass chromatography column. 0.5 g of resin will yield a bed height of about 2 cm in a column of the currently suggested dimensions. 5. Place a small filter frit 0.45- m pore size on top of the...

Extraction systems based on nonionic surfactants have been described as an alternative to the standard polymer polymer or polymer salt systems. Phase-forming surfactants are, for example, the nonionic polyoxyethylene-type detergents. This kind of aqueous two-phase system ATPS is simply induced by a switch in the temperature on the basis of the temperature-dependent reversible hydration dehydration of the polar ethylene oxide headgroups. A single isotropic micellar phase separates into two...

Many biological processes, such as regulation, catalysis, and complex formation, depend on the capacity of biopolymers to interact with apolar groups, i.e., their surface or effective hydrophobicity 1 . The determination of surface hydrophobicity is therefore important for understanding the mechanism of interaction of a biopolymer with its ligands. The determination of surface hydrophobicity is also important for designing a method for the purification or the concentration of biopolymers,...

Polymers PEG, a linear synthetic polymer of ethylene oxide units, and Dx, poly a-1,6-glucose , are the most commonly used polymers in the preparation of aqueous two-phase systems. Examples of other sugar polymers used are Ficoll polysucrose , pullulan and maltodextrins besides use of some derivatized carbohydrate polymers has also been reported including methylcellulose, hydroxyethylcellulose HEC , Reppal PES hydroxypropyl starch , benzoyl-dextran, dextran sulfate, and diethylaminoethyl DEAE...